A multi billion-dollar lawsuit, which has been ten years in the making, could be in jeopardy.

Apple is accused of abusing its monopoly position in the digital music player market, and only earlier this week lawyers claimed the firm had deliberately deleted rivals' songs from iPods.

But, the tech giant has launched an eleventh-hour challenge after presenting new evidence suggesting the women named as claimants may not have bought models covered by the suit - making the claims invalid.

Apple is accused of abusing its monopoly position in the digital music player market. Earlier this week, lawyers claimed it had deliberately deleted rivals' song from iPods from 2007 to 2009. But, the tech giant has challenged the suit after presenting evidence suggesting the plaintiffs' models of iPod may be invalid

If true, this could derail the long-running, class-action case over the tech giant's use of restrictive software that kept iPods from playing digital music sold by competitors to its iTunes store.

The case went to trial in California this week, after being filed a decade ago.

They are seeking $350 million (£224m) in damages, which could be tripled if the jury finds Apple broke federal anti-trust law.

Apple stopped using the particular software in question in 2009, which means the lawsuit only covers iPod models bought between September 2006 and March 2009.

This means the colourful iPod Nano, released in September 2009, and later generations of the devices are not covered.

After plaintiff Marianna Rosen gave evidence, Apple lawyers said they checked the serial number on her iPod Touch and found it was purchased in July 2009.

In a letter sent to the court late on Wednesday night, Apple lawyer William Isaacson said it appears the other plaintiff, Melanie Wilson, bought iPods outside the relevant time frame or, in one instance, purchased a model that did not have the specific version of software at issue in the case.

Opposing lawyers are not ready to give up the case, but US district judge Yvonne Gonzalez Rogers told both sides to file written arguments on whether the trial should proceed because she wants to begin considering the issue.

'I am concerned that I don't have a plaintiff. That's a problem,' the judge said at the end of the trial's third day of evidence in Oakland.

Mr Isaacson, who suggested the lawsuit could not proceed without a claimant, said he was asked for proof that either woman had purchased an iPod covered by the case.

Claimants say Apple's (co-founder Steve Job is pictured) restrictive software froze out competitors. Apple stopped using the software in 2009, which means the lawsuit only covers models bought until March 2009. But serial numbers show plaintiff Marianna Rosen's iPod was bought in July 2009

Plaintiffs' lawyer Bonny Sweeney said her side was checking for other receipts.

She conceded that Ms Wilson's iPods may not be covered, but also noted that an estimated eight million owners were believed to have bought the affected iPods.

APPLE'S U2 CONTROVERSY

This isn't the first time Apple has been in trouble for controlling music on devices.

Earlier this year, the firm automatically added U2's Songs of Innocence album to millions of iOS devices without permission.

In total, the album was added to iTunes Store customers in 119 countries.

Users took to Twitter and Facebook to express outrage at the plans and many moaned the album was difficult to remove from their devices.

In response, the tech giant now created a dedicated page that lets users remove the album by signing in with their Apple ID

Reports claim Apple paid the band $100 million as part of the deal.

The judge appeared irked at the last-minute hitch in a case that was originally filed nearly 10 years ago.

She said she was not ready to decide without further briefing, but indicated she did not want to leave the issue unresolved indefinitely.

Apple declined to comment on legal proceedings.

This isn't the first time Apple has been in trouble with users for controlling music on devices.

Earlier this year, the firm automatically added U2's Songs of Innocence album to millions of iOS devices without permission.

In total, the album was added to iTunes Store customers in 119 countries.

Users took to Twitter and Facebook to express outrage at the plans, and many moaned the album was difficult to remove from their devices.

In response, the tech giant created a dedicated page that lets users remove the album by signing in with their Apple ID.

This isn't the first time Apple has been in trouble for controlling music on devices. Earlier this year, the firm automatically added U2's Songs of Innocence album to millions of iOS devices without permission. It was then forced to create a dedicated page (pictured) that made it easy for disgruntled users to remove the files